Autonomous Omnidirectional Mobile Robot Research Articles

Autonomous omnidirectional mobile robot navigation based on hierarchical fuzzy systems

PurposeThis paper aims to propose a one-layer Mamdani hierarchical fuzzy system (HFS) to navigate autonomously an omnidirectional mobile robot to a target with a desired angle in unstructured environment. To avoid collision with unknown obstacles, Mamdani limpid hierarchical fuzzy systems (LHFS) are developed based on infrared sensors information and providing the appropriate linear speed controls.Design/methodology/approachThe one-layer Mamdani HFS scheme consists of three fuzzy logic units corresponding to each degree of freedom of the holonomic mobile robot. This structure makes it possible to navigate with an optimized number of rules. Mamdani LHFS for obstacle avoidance consists of a number of fuzzy logic units of low dimension connected in a hierarchical structure. Hence, Mamdani LHFS has the advantage of optimizing the number of fuzzy rules compared to a standard fuzzy controller. Based on sensors information inputs of the Mamdani LHFS, appropriate linear speed controls are generated to avoid collision with static obstacles.FindingsSimulation results are performed with MATLAB software in interaction with the environment test tool “Robotino Sim.” Experiments have been done on an omnidirectional mobile robot “Robotino.” Simulation results show that the proposed approaches lead to satisfied performances in navigation between static obstacles to reach the target with a desired angle and have the advantage that the total number of fuzzy rules is greatly reduced. Experimental results prove the efficiency and the validity of the proposed approaches for the navigation problem and obstacle avoidance collisions.Originality/valueBy comparing simulation results of the proposed Mamdani HFS to another navigational controller, it was found that it provides better results in terms of path length in the same environment. Moreover, it has the advantage that the number of fuzzy rules is greatly reduced compared to a standard Mamdani fuzzy controller. The use of Mamdani LHFS in obstacle avoidance greatly reduces the number of involved fuzzy rules and overcomes the complexity of high dimensionality of the infrared sensors data information.

Trajectory tracking with time-varying terrain conditions for an autonomous omnidirectional mobile robot using stratified variable structure saturated control

ABSTRACTThe trajectory tracking model of an autonomous omnidirectional mobile robot (ODMR) with different friction model for each wheel and motor dynamics is first achieved. Due to the fully actuated feature, the reference pose for ODMR is easily planned as compared with the under-actuated mobile robots. Subsequently, the reference motor current (RMC) is designed by the first switching surface. To make the motor current asymptotically track the RMC, a variable structure tracking control (VSTC) with the saturated output is designed by the second switching surface. The consideration of motor dynamics is to deal with the high-frequency motion behaviours of trajectory tracking, e.g. time-varying terrain, inaccurate friction model, discontinuous reference pose. The larger roughness of time-varying terrain, discontinuity of the reference pose or inaccurate friction model, the larger high-frequency amplitude of control input. In summary, the proposed stratified variable structure saturated control (SVSSC) includes the RMC and VSTC with the saturated output. The simulations for the circular trajectory with different nominal friction force and torque of each wheel and uncertainties by the SVSSC are satisfactorily achieved. The corresponding experiments with the mat on the reference trajectory and different reference pose for ODMR validate the effectiveness, robustness, and practicality of the proposed control.

Obstacle avoidance with translational and efficient rotational motion control considering movable gaps and footprint for autonomous mobile robot

This paper presents a sensor-based real-time obstacle avoidance method for an autonomous omnidirectional mobile robot based on simultaneous control of translational and efficient rotational motion considering movable gaps and the footprint. Autonomous mobile service robots that have been developed in recent years have arms that work and execute tasks. Depending on the task using moving parts, the shape of the robot (i.e., the footprint) changes. In this study, to improve the safety and possibility of reaching a goal even through a narrow gap with unknown obstacles, a sensor-based real-time obstacle avoidance method with simultaneous control of translational and efficient rotational motion (without unnecessary rotational motion) based on the evaluation of movable gaps and the footprint is proposed. To take account of the anisotropy footprint of the robot, multiple-circle robot model is proposed. In this paper, a novel control method based on fuzzy set theory is presented. To verify the effectiveness of the proposed method, several simulations and experiments are carried out.

Kinematics modeling and simulation of an autonomous omni-directional mobile robot

<p class="Abstractandkeywordscontent"><span lang="EN-US">Although robotics has progressed to the extent that it has become relatively accessible with low-cost projects, there is still a need to create models that accurately represent the physical behavior of a robot. Creating a completely virtual platform allows us to test behavior algorithms such as those implemented using artificial intelligence, and additionally, it enables us to find potential problems in the physical design of the robot. The present work describes a methodology for the construction of a kinematic model and a simulation of the autonomous robot, specifically of an omni-directional wheeled robot. This paper presents the kinematic model development and its implementation using several tools. The result is a model that follows the kinematics of a triangular omni-directional mobile wheeled robot, which is then tested by using a 3D model imported from 3D Studio</span><span lang="EN-US">®</span><span lang="EN-US"> and Matlab</span><span lang="EN-US">® for the simulation. The environment used for the experiment is very close to the real environment and reflects the kinematic characteristics of the robot.</span></p>

Development of a Mobile Robot for Transport Application in Hospital

We have been developing the Muratec Keio Robot (MKR), an autonomous omnidirectional mobile robot system for transport applications in the hospital domain. This robot has a chamber to transfer luggage, specimens, and other materials safely. The robot has sensor devices such as a stereocamera, laser range finder and ultrasonic sensors to recognize surrounding environment and user interfaces such as a touch panel display and a display scrolling messages for interaction with human beings. Experiments are carried out at hospitals to verify the performance of elemental MKR-003 technology. Experimental results confirmed that the robot canmove without colliding with static or moving obstacles in a hospital. This paper presents the omnidirectional mobile transfer mechanisms, bumper switch, elevator passenger system and transport information systems.

Implementation of Obstacle-Avoidance Control for an Autonomous Omni-Directional Mobile Robot Based on Extension Theory

The paper demonstrates a following robot with omni-directional wheels, which is able to take action to avoid obstacles. The robot design is based on both fuzzy and extension theory. Fuzzy theory was applied to tune the PMW signal of the motor revolution, and correct path deviation issues encountered when the robot is moving. Extension theory was used to build a robot obstacle-avoidance model. Various mobile models were developed to handle different types of obstacles. The ultrasonic distance sensors mounted on the robot were used to estimate the distance to obstacles. If an obstacle is encountered, the correlation function is evaluated and the robot avoids the obstacle autonomously using the most appropriate mode. The effectiveness of the proposed approach was verified through several tracking experiments, which demonstrates the feasibility of a fuzzy path tracker as well as the extensible collision avoidance system.

B309 自律全方位移動ロボットの自機と環境の高さ情報を考慮した並進と回転の同時制御(OS2 ロボットのダイナミクスと制御1)

B309 自律全方位移動ロボットの自機と環境の高さ情報を考慮した並進と回転の同時制御(OS2 ロボットのダイナミクスと制御1)

2A2-E10 ロボカップサッカー中型リーグにおけるSVMを用いた色認識パラメータの自動設定(ロボカップ・ロボットコンテスト)

RoboCup is an international project to promote AI, robotics, and related field. In RoboCup Soccer Middle Size League, the robots should recognize color and detect objects under the natural light condition. This paper presents an auto color calibration system using SVM (Support Vector Machine) for the autonomous omni-directional mobile robot. Our approach defines 5 classes of color (yellow, green, white, black, others). In our experiments, we compare the image binarized by human and the image binarized by SVM. This results more than 90% of recognition rate. We consider our approach can be useful in the RoboCup environment and we will improve it to run in real time.

Hierarchical Action Control Technique Based on Prediction Time for Autonomous Omni-Directional Mobile Robots

This paper proposes a multi time scale behavior control method for autonomous omni-directional mobile robot. As for motion planning, there are many problems to solve such as pass planning for a goal, moving by obstacle avoidance, keeping away from danger, and so on. The method is based on virtual potential field method. For each problem having a time scale, the corresponding module is constructed and virtual potential field is generated. Virtual force calculated from each potential field is used for generating the velocity command. The numerical simulations were carried out to verify the usefulness of the proposed method. From the results, it was confirmed that the robot can reach the destination without colliding with the static and moving obstacles by using the proposed method.

1P1-F26 ロボカップ中型リーグにおけるパーティクルフィルタを用いたロボットの自己位置推定

This paper presents a self-localization system based on particle filter for the autonomous omni-directional mobile robot. In 2008, the rules of middle size league were changed to goals without color. Therefore, we had to develop a new algorithm for self-localization. First, we introduce our line detection algorithm. Next, we explain the particle filter. Finally, we show the simulation results and the experimental results.

自律全方位移動ロボットの並進と回転の同時制御によるロボットサイズを考慮した障害物回避(機械力学,計測,自動制御)

This paper presents a real time collision avoidance method considering robot's size for an autonomous omni-directional mobile robot by simultaneous control of translational and rotational motions. This method enables the robot, which the size of width is not equal to that of length, to avoid unknown obstacles safely and efficiently in real time. To consider the difference between the width and length of the robot, the Capsule Case is newly introduced. In order to achieve the simultaneous control, this method employs an omni-directional platform. As an example of design method of the proposed method, novel control method based on the Fuzzy Potential Method is proposed. To verify the effectiveness of the proposed method, several numerical simulations and experiments are carried out.

FPGA Implementation of an Embedded Robust Adaptive Controller for Autonomous Omnidirectional Mobile Platform

This paper presents an embedded adaptive robust controller for trajectory tracking and stabilization of an omnidirectional mobile platform with parameter variations and uncertainties caused by friction and slip. Based on a dynamic model of the platform, the adaptive controller to achieve point stabilization, trajectory tracking, and path following is synthesized via the adaptive backstepping approach. This robust adaptive controller is then implemented into a high-performance field-programmable gate array chip using hardware/software codesign technique and system-on-a-programmable-chip design concept with a reusable user intellectual property core library. Furthermore, a soft-core processor and a real-time operating system are embedded into the same chip for realizing the control law to steer the mobile platform. Simulation results are conducted to show the effectiveness and merit of the proposed control method in comparison with a conventional proportional-integral feedback controller. The performance and applicability of the proposed embedded adaptive controller are exemplified by conducting several experiments on an autonomous omnidirectional mobile robot.

自律全方位牽引式搬送ロボットの開発

This paper presents a development of a novel traction and transfer mobile robot with omni-directional platform. In the environment where there are moving obstacles like human, the transfer robot has to arrive at the goal safely with a product. To solve this problem, the translation velocity and the rotation velocity are controlled independently. The translation velocity is decided based on the multi time scale behavior control method to avoid moving obstacles and the rotation velocity is decided based on the path direction. This method focuses attention on differences of time scales among problems that a robot confronts and is concretized through a modification of the virtual potential field method. For each problem having a time scale, the corresponding module is constructed and virtual potential field is generated. Virtual force calculated from each potential field is used for generating the velocity command. In this paper, this obstacle avoidance algorithm and a way to mount this algorithm on an autonomous omni-directional mobile robot with a scanner range sensor are described. To verify the effectiveness of the proposed method, the experiments of avoiding human using a robot with an omni-directional platform and a Laser Range Finder (LRF) were carried out.

1A1-A22 自律全方位移動ロボットの予測を用いた障害物回避行動の実験的検証(動作計画と制御の新展開)

1A1-A22 自律全方位移動ロボットの予測を用いた障害物回避行動の実験的検証(動作計画と制御の新展開)

Multi Time Scale Behavior Control Method for Autonomous Omni-Directional Mobile Robots

This paper proposes a multi time scale behavior control method for autonomous omni-directional mobile robot. As for motion planning, there are many problems to solve such as pass planning for a goal, moving by obstacle avoidance, keeping away from danger, and so on. The method is based on virtual potential field method. For each problem having a time scale, the corresponding module is constructed and virtual potential field is generated. Virtual force calculated from each potential field is used for generating the velocity command. The numerical simulations were carried out to verify the usefulness of the proposed method. From the results, it was confirmed that the robot can reach the destination without colliding with the static and moving obstacles by using the proposed method.

2P1-S-019 屋内通路環境における全方位移動ロボットのナビゲーション(車輪移動ロボット4,生活を支援するロボメカ技術のメガインテグレーション)

2P1-S-019 屋内通路環境における全方位移動ロボットのナビゲーション(車輪移動ロボット4,生活を支援するロボメカ技術のメガインテグレーション)

Self-diagnosis System of an Autonomous Mobile Robot Using Sensory Information

In this paper, we describe a basic sensing system for self-diagnosing an autonomous mobile robot. In recent years, many researches on intelligent robots and systems have been done. But, when such robots and systems work in the real environment, it is important for those robots and systems to have the ability to recognize their own conditions for detecting faults. On the point of view, we should consider pay more attention to diagnose in such intelligent systems. Therefore we try to construct an internal sensing system as a self-diagnosis system on a real robot. Especially, in this paper, we discuss about motor system of an autonomous omnidirectional mobile robot, which was developed in RIKEN. The self-diagnosis system consists of multiple sensors, which are voltage, current, encoder, and magnetic sensors. We show some diagnosing experimental results using the real system. From the results, we could collect basic data for fault detection of the system.